1. Field of the Invention
The invention relates to a toothbrush including a toothbrush body including a shaft-like handle, a head piece and a neck section, each being made of a first plastic material through injection molding, the neck section joining the head to the handle, and the head piece retaining a plurality of toothbrush bristles.
2. Description of the Related Art
Most of the various shapes of toothbrushes are already known. When used, the brush is rotated between the fingers holding it, depending on the various positions needed for the dental areas to be cleaned, and then securely held for the cleaning process itself. The holding of the toothbrush is generally done at the front end of the handle in front of the neck section joining the head of the brush, as the toothbrush is held between the thumb and index finger. This holding area customarily has a contour, possibly provided with a profiled portion, which favors advantageous holding of the brush in a "preferred" position or possibly in a position rotated 180 degrees to this. Intermediate positions require the hand or arm to be twisted, making it uncomfortable to carry out the cleaning movement which is intended.
In the art, it is known to have a toothbrush with one or more non-slip portions applied to the toothbrush body. Such portions are provided by a single point injection molding of elastic and/or non-slip material, e.g., rubber-like material, to fill recesses on the toothbrush body, thus forming the portions. However, "single point injection molding" implies that when two or more areas or recesses are to be filled in order to create such portions, there must be a material flow channel or channels available between such areas or recesses on the body in order to enable the material to flow into the areas or recesses in such a single shot, single point injection molding step. However, such channels in most cases are aesthetically non-satisfactory, and more than often a matter of design trade-off. Further, especially for toothbrush handles made of transparent material and in cases where a more flexible approach in toothbrush design is desired, such channels will in some cases cause the toothbrush body to be structurally weaker at the location of such channels or adjacent thereto, in particular at the neck region of the toothbrush body. In particular, if both the head and handle of the toothbrush are to have regions of such elastic and/or non-slip material, the prior art method of using single point injection molding of such material will result in a toothbrush having a structurally weakened neck because of the material flow channels located in the neck.